Buffered Lighters vs. System.out.println() Performance Comparison

This article examines the performance comparison between BufferedWriter vs. System.out.println().

BufferedWriter and System.out.println(), the representative classes responsible for output in Java, work in different ways internally.

BufferedWriter

BufferedWriter stores the output data in a buffer and outputs it at once when it becomes a certain size or flush() is called.

This approach serves to optimize performance by combining multiple small output tasks into one large task.

Advantages

• High performance when outputting large amounts of data
• Save CPU resources by reducing unnecessary I/O calls

Disadvantages

• Output only occurs when flush() is called
• Outputting small amounts of data can lead to overhead

System.out.println()

System.out.println() uses PrintStream internally to output data immediately.

However, since this PrintStream is buffered internally, it can also work faster than BufferedWriter in simple outputs.

Advantages

• Ready to output
• Fast output of small amounts of data

Disadvantages

• Repeated output of large amounts of data can degrade performance
• Performance optimization is not as automatic as BufferedWriter

Conclusion

If the amount of output data is small, BufferedWriter may perform worse than System.out.println().

This is due to the unnecessary overhead of calling flush() without taking advantage of buffering.